*::after, *::before {
  box-sizing: border-box;
}

*{
  margin: 0;
  padding: 0;
  box-sizing: border-box;
  scroll-behavior: smooth;
}

body {
  display: flex;
  justify-content: center;
  align-items: center;
  min-height: 100vh;
  background-color: #151517;
}

nav {
  position: relative;
  display: flex;
  gap: 30px;
  background: #222327;
  padding: 15px 60px;
}

nav a {
  position: relative;
  color: #999;
  text-decoration: none;
  font-size: 1.5em;
  z-index: 2;
  height: 75px;
  display: flex;
  justify-content: center;
  align-items: center;
  padding: 0 30px;
  transition: .5s ;
}

nav a.active {
  color: #222327;
}

#indicator {
  position: absolute;
  height: 75px;
  width: 150px;
  background: #29fd53;
  z-index: 1;
  transition: .5s;
  /* display: none; */
}

#indicator::before {
  content: '';
  position: absolute;
  left: -30px;
  width: 50px;
  height: 15px;
  background: #29fd53;
  border-radius: 15px;
  box-shadow: 15px 30px #29fd53,
    5px 60px #29fd53,
    -15px 15px #222327,
    -10px 45px #222327;
  transition: .5s;
}

#indicator::after {
  content: '';
  position: absolute;
  right: -30px;
  width: 50px;
  height: 15px;
  background: #29fd53;
  border-radius: 15px;
  box-shadow: 5px 30px #29fd53,
    -15px 60px #29fd53,
    15px 15px #222327,
    10px 45px #222327;
  transition: .5s;
}

#indicator.change::after {
  right: -20px;
  box-shadow: 10px 30px #29fd53,
    20px 60px #29fd53,
    15px 15px #222327,
    25px 45px #222327;
}